Design and material selection of a CO₂-powered beverage cooler

Abstract

While training for a triathlon, 6-hour bike rides come with the territory. As a result, protein-based drinks are a must to keep nourished. Currently, the only way to keep a drink from spoiling is to have an insulated bottle. However, this does not actively keep the drink cool; it simply slows the rate of warming. This experiment was designed to create a drink holder that would use CO2 to actively cool a drink to maintain a desired temperature. To do this, coiled copper tubing was inserted into an insulated housing with a CO2 source attached to the other end. Between the combination of the insulated housing and CO2 bursts, the rate at which the drink warms is slowed and even reversed when CO2 is used. We hypothesized the concept that CO2 would actively cool the drink inside the bottle, and experimentation proved this to be accurate. Once proof of concept was established, the next step was to optimize when and how much CO2 was needed to maintain the desired temperature inside the bottle. Ultimately, smaller double bursts were found to be the most effective way of maintaining the temperature of the drink. Depending on the size of the CO2 bottle used, drinks are able to maintain proper temperatures up to 3-4 times longer than by insulation alone. This is significant because it shows the concept doesn't just work, but it makes a considerable difference from merely insulating the bottle. This experiment provided positive results, allowing future work to be focused on the ergonomics and practicality of the final design.